Optical techniques for observing substrate characteristics resulting from microfabrication processes such as thermal oxidation processes, chemical and physical vapor deposition processes of various kinds, epitaxy, photolithography and masking of various kinds, dry and wet etching processes of various kinds, laser ablation, focused ion beam milling and other similar techniques that are used to create or modify structures having features with critical dimensions on the order of a few micrometers or nanometers tend to be rather inflexible. Non-imaging techniques such as ellipsometry, scatterometry, and reflectometry permit the assessment of substrate or sample characteristics on a very small scale. However these techniques are generally useful only for the assessment of characteristics below a certain size or dimension, e.g. layer thicknesses on the order of a 10's or 100's of nanometers, structural features of a size that is on the order of the wavelength of light used to assess the structures and which generally are repetitive in nature or for particles that of a generally known type. These techniques are data intensive and require a large investment in mathematical models of specific structures and the hardware that can rapidly manipulate such models. Other non-imaging techniques such as laser triangulation are capable of locating small structures of a substrate when used as a scatterometer, but tend to be most useful for larger structures having dimensions that are larger than the wavelength of light being used for sensing purposes. The small spot size of a laser triangulation system allows one to build up a geometry of a structure that is assessed only on a point by point basis. Geometries of structures that interfere with the reflection of a fine beam (spot or line) of light become difficult to assess using this technique. Imaging techniques for assessing structures are limited to the native resolution of the optical system used to capture an image and also by the fact that the higher the resolution of the optical system, the more difficult it becomes to capture an image of an object that has a three-dimensional structure; the depth of focus of a higher resolution optical system limits the amount of a 3D structure that can be captured with the requisite focus needed to resolve structures of the object that fall outside the region that is in good focus. Accordingly, it is desirable to provide an approach to characterizing microfabrication processes in an accurate and efficient manner.